The Chance of a Lifetime (Musaicum Romance Classics). Grace Livingston Hill

Sherrill and Alan grew up together and have been friends ever since. Sherrill gets invited to visit her wealthy relatives in New York and Alan is offered to take part in an important archaeological mission in Egypt at the same time. What seems as a chance of a lifetime for both soon turns out to be the complete opposite. Sherrill and Alan realize that the only true happiness is when they are together.